M&D i dont budget (we are lucky that we dont need to either but i am always conscious of how and when we spend. to me there are things that I am not sure you have factored in.

Does bills cover elec gas water insurance (car, contents, health) $5200 pa wouldn't cover our bills for that

Not sure what credit card covers - is it a debt or just miscellaneous expenses - maybe it would be worth you actually categorising what that expenditure is.

Also, things like coffees, bought lunches ($10 each a day is $200 a fortnight) meals out, haircuts (DH and my haircuts cost $150 combined every 6 weeks which is $50 a fortnight) all add up really quickly.

Maybe make a deal with your DH where you write down everything you spend money on for a month and see where the leakage is.